Cam lock assemblies are well known in the art and are usually used in mailboxes or electrical equipment or in any such installations having panel type doors and frames fabricated from sheet metal.
Cam lock assemblies usually comprise a rotatable lock cylinder disposed in a threaded sleeve having at least one flat or other formation which matches the noncircular outline of an opening formed in the door or frame of the equipment to be locked, the formation acting to keep the sleeve from rotating. The cylinder is provided with an elongated camming tongue fixed at one end thereto and which rotates with the cylinder between an unlocked position, in which the tongue lies wholly within the outline of the portion of the equipment on which the cylinder is mounted, and a locked position, in which the tongue extends from the one portion to the other portion of the equipment and engages therewith in a camming manner which draws the two portions of the equipment into abutment with one another.
One disadvantage with this type of locking system is that forced entry can be had by inserting a tool between the movable and stationary portions of the equipment to engage the tongue, which can then be bent out of engagement with the equipment, leaving same in an unlocked state.